WASHINGTON -LRB- CNN -RRB- -- The U.S. Navy has charged six guards accused of assaulting detainees in May at Camp Bucca in Iraq , naval officials said Thursday .

U.S. guards patrol at Camp Bucca in Iraq in May .

The Army Criminal Investigation Division investigated alleged incidents that left two detainees with minor bruises .

The division also investigated an incident in which eight prisoners were confined overnight to a housing cell that had been sprayed with a riot control agent , the Navy said .

The six guards will face courts-martial . Seven other cases have been resolved through nonjudicial punishment , according to a statement from the commander of U.S. Naval Forces-Central Command .

The courts-martial are expected to start within 30 days at Camp Bucca , which is in southern Iraq near the Kuwaiti border .

The guards accused in the case are assigned to Navy Provisional Detainee Battalion 4 .

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Navy guards accused of assaulting detainees at Camp Bucca

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Eight prisoners were confined to cell sprayed with riot control agent , Navy says

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Navy : Two detainees allegedly left with minor bruises